The family of an FBI agent who disappeared from his Burbank home more than a month ago made an emotional plea on Wednesday for the public’s help in preventing the case from going cold.

It was the second time the family of Special Agent Stephen Ivens appealed for help in tracking down Ivens’ whereabouts since he went missing May 11, seemingly vanishing despite a massive manhunt by foot and air in the days after his disappearance.

The active, on-the-ground searches have long been called off, and authorities say few, if any, leads have come in.

The family has since launched its own search effort, aided in large part by social media websites and campaigns.

Standing at the base of a popular hiking trail at the Stough Nature Center in Burbank on Wednesday, Ivens’ wife, Thea, called for volunteers to assist with two searches organized by the family on June 16 and 23.

“We can’t do that alone,” she said, adding that the family was “still hoping” her husband would come home.

“My understanding is that if there are no leads, there are no searches,” Thea Ivens said. “Lately there have not been any tips or leads.”

Her appeal came one day before Stephen Ivens’ 36th birthday.

The agent, who specializes in national security, disappeared from his Burbank home in the 1700 block of Scott Road, prompting a massive search that involved about 100 FBI agents and 50 local law enforcement officials who initially focused on the nearby Verdugo Mountains.

The search took on added urgency because officials said Ivens likely had his department-issued gun and could be a danger to himself, although they declined to say why.

The family has been conducting their own search of the Verdugo Mountains, soup kitchens in Santa Monica and Venice Beach, and homeless shelters, Thea Ivens said.

The Burbank Police Department — the lead agency on the case — told the family detectives were reviewing tapes from the downtown Burbank Metrolink Station for possible leads, said Jim Ryan, Stephen Ivens’ uncle, who was also at the press conference Wednesday.

Thea Ivens recounted how she called 9-1-1 on May 11 to report Ivens missing after finding a letter addressed to her and their son.

It was a gratitude letter, Thea Ivens said, “telling me that our child and I are the greatest gift that God has given him. It was a message for Kyle to be honest, gracious and humble and that if you are that, you can sleep at night.”

She added that she felt “undertones” that her husband “would be gone for a while, but he didn’t exactly say goodbye — he didn’t say that.”

Since February, Thea Ivens said her husband had not been able to sleep and in April, began experiencing anxiety attacks.

She said the attacks had nothing to with his work, although she acknowledged that there were “some incidents at the workplace.”

FBI spokeswoman Laura Eimiller on Wednesday reiterated that the investigation was ongoing, and that it would continue “until Stephen Ivens is found.

“Many leads were generated based on the initial media coverage, as well as by fliers handed out to hikers and the FBI’s publicity efforts,” she added.

Burbank Police Capt. Denis Cremins said search efforts were being directed based on credible information, adding that all leads have been run down to their conclusion.

“We haven’t come up with anything, and certainly welcome any credible leads,” he said.

A photograph of Stephen Ivens, an FBI agent, who was last seen on May 10, 2012. Bloodhounds last traced his scent of smell at the base of a popular hiking trail near Stough Canyon Park Nature Center in Burbank.